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  <TITLE>Diff, Match and Patch: Demo of Diff</TITLE>
  <SCRIPT TYPE="text/javascript" LANGUAGE="JavaScript" SRC="../javascript/diff_match_patch.js"></SCRIPT>
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<BODY>
<H1>Diff, Match and Patch</H1>
<H2>Demo of Diff</H2>

<P>Diff takes two texts and finds the differences.  This implementation works on a character by character basis.
The result of any diff may contain 'chaff', irrelevant small commonalities which complicate the output.
A post-diff cleanup algorithm factors out these trivial commonalities.</P>

<SCRIPT TYPE="text/javascript" LANGUAGE="JavaScript">
var dmp = new diff_match_patch();

function launch() {
  var text1 = document.getElementById('text1').value;
  var text2 = document.getElementById('text2').value;
  dmp.Diff_Timeout = parseFloat(document.getElementById('timeout').value);
  dmp.Diff_EditCost = parseFloat(document.getElementById('editcost').value);

  var ms_start = (new Date()).getTime();
  var d = dmp.diff_main(text1, text2);
  var ms_end = (new Date()).getTime();

  if (document.getElementById('semantic').checked) {
    dmp.diff_cleanupSemantic(d);
  }
  if (document.getElementById('efficiency').checked) {
    dmp.diff_cleanupEfficiency(d);
  }
  var ds = dmp.diff_prettyHtml(d);
  document.getElementById('outputdiv').innerHTML = ds + '<BR>Time: ' + (ms_end - ms_start) / 1000 + 's';
}
</SCRIPT>

<FORM action="#" onsubmit="return false">
<TABLE WIDTH="100%"><TR>
  <TD WIDTH="50%">
<H3>Text Version 1:</H3>
<TEXTAREA ID="text1" STYLE="width: 100%" ROWS=10>I am the very model of a modern Major-General,
I've information vegetable, animal, and mineral,
I know the kings of England, and I quote the fights historical,
From Marathon to Waterloo, in order categorical.</TEXTAREA></TD>
  <TD WIDTH="50%">
<H3>Text Version 2:</H3>
<TEXTAREA ID="text2" STYLE="width: 100%" ROWS=10>I am the very model of a cartoon individual,
My animation's comical, unusual, and whimsical,
I'm quite adept at funny gags, comedic theory I have read,
From wicked puns and stupid jokes to anvils that drop on your head.</TEXTAREA></TD>
</TR></TABLE>

<H3>Diff timeout:</H3>
<P><INPUT TYPE="text" SIZE=3 MAXLENGTH=5 VALUE="1" ID="timeout"> seconds<BR>
If the mapping phase of the diff computation takes longer than this, then the computation
is truncated and the best solution to date is returned.  While guaranteed to be correct,
it may not be optimal.  A timeout of '0' allows for unlimited computation.</P>

<H3>Post-diff cleanup:</H3>
<DL>
<DT><INPUT TYPE="radio" NAME="cleanup" ID="semantic" CHECKED>
<LABEL FOR="semantic">Semantic Cleanup</LABEL></DT>
<DD>Increase human readability by factoring out commonalities which are likely to be
coincidental.</DD>
<DT><INPUT TYPE="radio" NAME="cleanup" ID="efficiency">
<LABEL FOR="efficiency">Efficiency Cleanup</LABEL>,
edit cost: <INPUT TYPE="text" SIZE=3 MAXLENGTH=5 VALUE="4" ID="editcost">
<DD>Increase computational efficiency by factoring out short commonalities which are
not worth the overhead.  The larger the edit cost, the more agressive the cleanup.</DD>
<DT><INPUT TYPE="radio" NAME="cleanup" ID="raw">
<LABEL FOR="raw">No Cleanup</LABEL></DT>
<DD>Raw output.</DD>
</DL>

<P><INPUT TYPE="button" onClick="launch()" VALUE="Compute Diff"></P>
</FORM>

<DIV ID="outputdiv"></DIV>

<HR>
Back to <A HREF="http://code.google.com/p/google-diff-match-patch/">Diff, Match and Patch</A>

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